An electroencephalogram (EEG) is a test that measures electrical activity in the brain. It involves placing small electrodes on the scalp, which detect and record brain waves. This information helps doctors understand brain function and diagnose conditions like epilepsy, sleep disorders, and other neurological issues. EEGs are non-invasive and typically take about 20 to 40 minutes. During the test, patients may be asked to relax, open or close their eyes, or perform specific tasks. The results are displayed as wave patterns, which can reveal abnormalities in brain activity and assist in treatment planning.